Hi Prashant
I'm pretty sure we asked this question on Cheryl's webinar and the response she gave at the time is that the cadence time zone is set to your org default (it's confusing and somewhat unfortunate that EST can mean different things depending on if you are American or Australian!)
I've just checked mine, and it is set to Australian Eastern Standard Time, like my org default.
Maybe there was some other reason your emails didn't fire?
Cheers
Veronica